It is known that parallelepipedic structures made of double twisted metal mesh, known as gabions, are employed for coverings and protective structures for preventing erosion of areas of ground caused by surface water and water filtering through the ground, and for the construction of works to contain areas of ground, and for the control of landslides or the like, for river, lake, coastal, mountain, road and other defences.
Such gabions, which are resistant to corrosion and to mechanical stresses. are joined together, filled in situ with stones and soil or other particulate materials, and closed with an appropriately fixed lid of metal mesh, and constitute natural defences and reinforcements suitable for environmental restoration of degraded parts of areas at risk from landslides.
A feature common to all these structures is that they are composed of prefabricated containers in double-twisted metal mesh composed of bottom and side panels, partitions and upper closure panels. The containers are manufactured at suitable plants for the production of the metal mesh, with the appropriate operations of weaving and reinforcing the extended sheets and folding them in a manner suitable for easier transport and storage, with minimum bulk.
In use, they are filled with stones or the like, closed by the upper lid or panel, joined together and, if appropriate, placed one above the other.
A system is also known for obtaining the above mentioned results comprising special closed "mattress gabions", that is to say box-type containers of large surface area and small thickness, having multiple partitions or compartments able to cover, with no continuity, very extensive areas of land, in order to protect them from erosion.
Also known is the system of "Reinforced Earth", which employs flat curtain walls intended to support areas of ground by means of anchoring strips.
By means of the abovementioned known techniques, which entail more or less difficult and costly operations, composite structures are obtained having an outer face in the manner of a wall, more or less inclined or in stepped form, while the inner, uphill side is arduous to manufacture because of the need to produce secure anchoring points in the ground.